Brown said in his written decision he did not believe Davis, who is in prison for taking part in two Manson family murders, "was just a reluctant follower who passively went along with the violence."

"Until Davis can acknowledge and explain why he actively championed the family's interests and shed more light on the nature of his involvement," Brown went on, "I am not prepared to release him."

FOR THE RECORD: An earlier version of this article said Bruce Davis was convicted for his role in the killing of aspiring musician George Hinman. The victim's name was Gary Hinman.

This is the second time Davis has been granted parole and then had it overturned by a governor. Arnold Schwarzenegger in 2010 cited similar reasons for keeping the convicted murderer imprisoned. A state appeals court ultimately upheld that decision.

Davis' lawyer, Michael Beckman, said Friday that he will probably appeal again. Davis is eligible for another parole hearing as soon as October.

Beckman said Brown's decision was political and his stated rationale for continuing to keep Davis, now 70, behind bars would be "laughable if the consequences for my client weren't so devastating."

Davis told a parole board in October 2012 that he had been accepted into two transitional programs in Los Angeles, including one that specializes in helping paroled murderers adjust. He said that if freed, contending with negative publicity would be likely to pose one of his biggest challenges.

Parole hearing transcripts show that over the years, Davis gave conflicting accounts of his role in the murders he was convicted of and minimized his involvement in the Manson group. They also show that Davis has used the past four decades to earn a doctoral degree in religion, graduating summa cum laude, and completed vocational training in drafting and welding.

He participated in therapy and self-help programs, married and fathered a child.

Davis, 26 at the time of the murders, was convicted in 1972 for taking part in the killings of aspiring musician Gary Hinman and ranch hand Donald "Shorty" Shea, who also worked as a Hollywood stuntman.

Details of Shea's killing, which had always remained murky, were further confused by Davis' recent assertion that it took place on a day and at a location that differed from prosecutors' claims. Another Manson family member, Steve "Clem" Grogan, was convicted along with Manson and Davis of killing Shea.

In 1985, Grogan became the only Manson family member convicted of murder to win parole, after directing law enforcement to Shea's body.